Control system



v INVENTOR B RAE/emu Patented Mar. 16, 1943 CONTRQL SYSTEM Robert 1).Shaw, Bloomfield, Conn, assignor to Niles-Dement-Pond Company, WestHartford,

Conn., a corporation of New Jersey Application May 31, 1940, Serial No;338,035 4 Claims. (01. elf-13.5)

This invention relates to an electrically operated control fora motor.driven' membersuch as a feed shaft or screw for a machinetool so thatthe member may be rotated in either direction,

its rotation reversed and quickly stopped while 5 the motor continues torotate.

A primary object of the invention is to provide driving connections fora shaft or screw including a driving motor therefor having its rotordirectly coupled to a magnetic clutch, the armature for the clutch beingconnected, preferably through gearing, directly to the shaft or screw.

A feature that enables me to accomplish the above named object is thatcontacts are opened and closed, as by a tracer, closure of eithercontact serving to start rotation of the motor in one or the otherdirection and also to simultaneously energize the clutch to drivinglyconnect the motor to the shaft. When either contact is opened,

however, the clutch isinstantly deenergized so that the shaft or screwis disconnected from the motor a'nd'the shaft will not overrun while themotor may continue to rotate.

Another object of the invention is to operate the control for the motorand clutch through a reversing switch or relay, the contacts for theswitch being on a walking beam so that but one pair of contacts can beclosed at any one time, these contacts in turn controlling solenoidoperated'switches for the motor armature circuit to control be extremelysensitive and flexible so that 5 as the tracer moves over a model ortemplate the movable machine member may, be promptly stopped when thetracer contacts with or moves away from the model. In the presentcontrol system stopping of the movable member is ef- 40 fected by thedeenergizing of a magnetic clutch. In the reproduction of many shapes ina vertical milling machine or die sinker from a model or template areversal of'movement of the movable movement of another member iscompleted.

Thereafter the machine member controlled directly from the tracer may berequired to move again in the same direction so that reversal of themotor would not be required. Opening of a tracer contact therefore doesnot stop or reverse the rotation of the motor. This rotation continuesuntil a further movement of the tracer contact eflects closing of an ppContact may include: First, a motor; second, a magnetic which againenergizes the clutch and starts rotation of the motor in the reversedirection.

Another Lobject of the invention is to control a magnetic brakeassociated with a magnetic clutch, both brake and clutch beingcontrolled by tracer contacts and-the "brake being energized when theclutch is deenergized and vice versa.

And finally it is an object of the invention simultaneously to energizea clutch and start rotation of a motor in\ either direction, the brakebeing at the same time released; or to disengage I the clutch and applythe brake, the motor continuing to rotate in the same direction untilanother contact is closed.

More 'particularly'the invention relates to the control of an automaticreproducing machine by alternately opened and closed tracer controlledcontacts such as employed in the tracer controlled machine shown inpatent toShaw, 1,683,- 581, granted September 4, 1928; and this application is a continuation in part of my Patent 2,232,- 740 granted February25, 1941.

With the above and other objects in view the invention may include thefeatures of construction and operation set forth in the followingspecification and illustrated in the accompanying drawing.

In the accompanying drawing annexed hereto and forming a part of thisspecification I have shown the invention embodied in the essentialelectrical circuits for a machine of the type shown in the abovereferred to patent, but it will be understood that the invention can beotherwise embodied and that the drawing is not to be construed asdefining or limiting the scope of the invention, the claims appended tothis specification being relied upon for that purpose.

In the drawing the figure shows a wiring diagram for individuallycontrolling the motor clutch and brake for rotating a screw in oppositedirections by the motor and for stopping the screw, these members beingcontrolled from contacts opened and closed by movement of a member whichmay comprise a tracer of a type shown in theabove referred to patent.

In the above mentioned drawing there has been shown but one embodimentof the invention which is now deemed preferable, but it will beunderstood that'changes and modifications may be made within the scopeof the appended claims :vithout departing from the spirit of theinvenion.

Briefly and in its broadest aspect my invention olutch rotated directlytherefrom; third, a magnetic brake: fourth, a shaft or screw drivinalyconnected to the armature of the clutch; fifth,

a tracer, movement of which to and from a centraJ. position opens andcloses contacts of relay motor in either direction.

Referring more in particular to the diagram,

the motor I9 may be of any suitable type having its field windingssupplied with current from a suitable source by lead wires II and i2. Asthe direction of rotation of the motor i9 is preferably controlled byreversing the direction of the current in the armature windings only theleads II and i2 from a suitable source of current may be permanentlyconnected to the motor l9. Mounted on the motor armature shaft II forrotation therewith is a magnetic clutch |4 supplied with current frombrushes l9 engaging slip rings l9 on the clutch. The circuit for thebrushes II will presently be more fully described. Adjacent the magneticclutch body I4 is the armature i1 therefor mounted on and for rotationwith a shaft l9, this shaft 9 being drivingly connected to a shaft orscrew l9 as by means of the gearing 20. Armature "when the magneticclutch I4 is energized is drawn toward and forced to rotate with theclutch |4 so that screw I9 is rotated whenever the circuit for thebrushes I9 is closed and the motor 9 is rotated.

The motor i9 is rotated in opposite directions depending upon theconnections to its armature windings through lead wires 2| and 22connected through either of two solenoid switches 29 and 24 of the threepole type to a source of current by connections forming part of thecontrol circuits forming the present invention. These circuits willpresently be more fully described.

To energize the circuits for the magnetic clutch l4 and the armaturewindings of the motor ill contacts 29 and 21 opened and closed bymovements of a tracer 29 are employed. The tracer 29 is shownfragmentarily only and its movements from the position shown in thediagram oscillate a lever 29 which, as shown, is grounded. As theoperation of the tracer 29 upon the lever 29 and the mounting of thelever 29 are or may be similar in every way to the construction shown inFig. 16 of the above referred to patent, further description is notthought to be necessary. The circuits for the clutch |4 includeconductors 49, 99, 9| and 92, the brushes i5, conductor 99, relayoperated switch 94 and conductor 99. Conductors 49 and 95 are connectedto the main leads L+ and L respectively and conductor 99 includes arelay operating solenoid Presently to be described. With the tracer inthe position shown, switch 34 is drawn to its closed position bysolenoid 39 which is energized by current from a small groundedgenerator 91 through conductor 39, conductor 39, including one pole ofswitch 24, and contactor 29 to the grounded lever 29. With the contact21 closed a circuit is closed to solenoid 40 adjacent solenoid 99through conductor 99, conductor 4|, including one pole of switch 29 tothe grounded lever 29. With either contact 29 or 21 closed, therefore,switch 94 will be closed and the clutch |4 energized.

To energize the motor windings through leads 2| and 22 the solenoid forswitch 29 or 24 is closed by a circuit including one or the other ofcontactors 42 or 49 of a reversing switch 13 connected by a walking arm44 so that but one contact 42 or 49 may be closed at any instant. Thecoils 99 and 92 for contactors 42 and 49 respectively are connected tothe leads L+ and L- by conductors 49, 49, 41, 49, resistance 49 andconductors l9 and 9|. By short circuiting either solenoid 92 or 99 theopposite contactor will be closed. With contactor 49 closed as shown,switch 24alsowillbeclosedssshownbyacircuitineluding conductors 49, 99.9|, 99, 99, 44, 94 and 9|. The motor will therefore be energised forrotation in one direction. This circuit includes conductors 49,99,switch 24, lead 22, lead 2|, switch 24 and conductors 91 and 9|. Withcontactor 42 closed, circuits to the leads 2| and 22 will be closed butin the opposite direction and throush switch 29 so that the motor IIwill rotate in the opposite direction.

Coils Irene! 99 of the switches 49 and 42 are connected in a circuit tothe main leads L+ and L by conductors 49, 49, 41, 49, resistance 49 andconductors 99 and II. To short circuit either coil 92 or 99, circuitsincluding switches 99 and 99 are employed. Switch 99 is closed by acircuit from aenerator 91 through conductors 99, 99, 9|. solenoid 92 andconductor 99 to the contact 29 and grounded lever 29. Whenever contact29 is closed, therefore, the motor will be rotated in one direction.With contact 21 closed, switch 99 will be closed by a circuit fromgenerator 91 throughconductor 99 to the solenoid 94, and conductor 99 tothe grounded lever 29. With either switch 99 or 99 closed,"a circuitwill be closed to short circuit one or the other of the contactor coils99 or 92. Switch 99 when closed short circuits coil 99 and switch 99when closed short circuits coil 92.

Adjacent the magnetic clutch I4 is abrake 91 of the magnetic type thebody of which is secured in any preferred manner to the casing 99surrounding the clutch. when the coil of this brake 91 is energized thearmature I1 is pulled away from clutch |4 into contact with the brake 91which stops rotation of ture l1 and shaft II.

The circuit for energizing the brake coil 91 includes a relay 99. Whenthere is no current in the circuit referred to above for the clutchmagnet the relay 94 is up, as there is no current in either solenoid 99or 49; the solenoid 19 inserted in conductor 99 is therefore notenergized and the relay 99 is held in its upper position by its spring.In this position the circuit for the brake coil is energized and thebrake is applied to the armature l1. As soon, however, as the tracerlever 29 closes either of its contacts solenoid 99 or 49 is energizedwhich forces its relay 94 to its lower or operative position and closesthe circuit to the brake solenoid 19, thus energizing it and forcing itsrelay 99 tb its lower or open position and opening the circuit to thecoil of the brake 91. As long as contacts 29 and 21 are simultaneouslyopen, relay 94 will be open and solenoid 19 deenergized so that relay 99will be up to close the circuit to the brake. As shown in the diagramthe leads for the brake circuit may be connected on one side directly toconductor 99 and on the other side from the relay 99 to the plus line bya conductor 1|.

In operation when a tracer controlled contact 29 or 21 is opened therelay 94 for the clutch circuit is promptly opened which instantlydeenergizes the magnetic clutch l4 and breaks the connection between themotor l9 and screw l9. Simultaneously the brake is energized and lothearmatation of the armature I1 and shaft I8 is stopped. The contactors 42and 43 of the reversing switch nected thereto, a magnetic brake adjacentsaid clutch, an armature for said clutch and brake will remain in thesame position for the reason I that, although switch 58 or 59 has openedand both coils 52 and 53 are energized, the closed 'contactor will beheld closed for the reason that a circuit to draw the relay 34 down toclose the magnetic clutch circuit so that the clutch i4 is thereforereenergized and the brake 'deenergized. This movement of the tracer 28also closes relay 59 and raises contactor 42 at the left of the walkingbeam 44 by short circuiting the opposite coil. The solenoid switch 23 atthe left of the walking beam 44 is therefore closed which closes thearmature circuit to leads 2|, 22 in the opposite direction. Rotation ofthe motor therefore takes place in the opposite direction and thisrotation continues so long as this tracer contact 21 in the diagram isclosed. As soon as either tracer contact 26 or 21 is opened the clutchI4 is deenergized but rotation of the motor ill will continue in thesame direction until the opposite contact on the tracer lever 29 isclosed.

, Continuedrotation of the motor, however, has

no eifect upon rotation of the shaft l9, as the clutch M has beendeenergized.

What I claim is:

l. A control system comprising in combination, a motor, a magneticclutch drivingly connected thereto, a magnetic brake adjacent saidclutch, an armature for said clutch and brake connected to a shaft forrotation therewith whereby rotation of said armature will rotate saidshaft, tracer controlled contacts, relays controlled by said contacts toopen and close circuits to simultaneously energize said clutch and startrotation of said motor in a predetermined direction, and relaycontrolled circuits to deenergize said clutch and energize said brakewhen said contacts are simultaneously opened.

2. A control system comprising in combination, a motor, a magneticclutch drivingly con- "connected to a shaft whereby rotation of saidarmature will rotate said shaft, tracer controlled contacts, circuitscontrolled by said tracer contacts to simultaneously energize saidclutch and start rotation of said motor in a predetermined, direction,said circuits deenergizing said clutch and applying said brake-when saidcontacts are simultaneously open, and circuits controlling said motorrotation and reversing said rotation when one tracer contact is openedand an opposite contact is closed.

3. A control system comprising in combination, a motor, .a magneticclutch drivingly connected thereto, a magnetic brake adjacent there to,an armature for said clutch and brake connected to a shaft wherebyrotation of said armature will rotate said shaft, tracer controlledcontacts, circuitscontrolled by said tracer contacts to simultaneouslyenergize said clutch and deenergize said brake and start rotation ofsaid motor in a predetermined direction, and circuits controlled by theopening of one of said contacts to deenergize said clutch and energizesaid brake while said motor continues to rotate in the same 7 clutch androtate the motor in the reverse direction.

4. A control system comprising in combina tion, a motor, a magneticclutch drivingly connected thereto, a magnetic brake adjacent thereto,an armature for said clutch and brake connected to a shaft wherebyrotation of said armature will rotate said shaft, tracer controlledcontacts, circuits controlled by said tracer contacts to simultaneouslyenergize said clutch and deenergize said brake and start rotation ofsaid motor in a predetermined direction, and circuits controlled by theopening of one of said contacts to deenergize said clutch and energizesaid brake while said motor continues to rotate in the same direction aslong as both contacts are open, said circuits when an opposite tracercontact is closed being adapted to reenergize said clutch and rotate themotor in the reverse direction.

ROBERT D. SHAW.

